4o8 
ZOOLOGY OF THE FAR EAST. 
female, the first pair of pleopods are only one-branched instead of two-branched as 
described b}^ Nakazawa. The species is known, so far, only from Japan and 
Formosa. 
"Among large quantities of Acetes japonicus, Kish., on sale in the market, 
probably from the mouth of the Yeddo River. N. A." 
Sub-f am RHOPA LOPHTHALMINA E. 
Genus Rhopalophthalmus, Illig, 1906. 
Rhopalophthalmus egregius. Han.sen. 
R. egregius, Hansen, 1910. p. 49, pi. vi. figs. 3a-k, pi. vii, figs. la-d. 
R. egregius, Nakazawa, 1910, p. 255. pi. viii, figs. 12, 22 
R. egregius, Tattersall, 19 15, p. 151. 
R. egregius, Colosi, 1918, p. 6, 
Locality.—Coast of Ariak Sea, Japan, several fathoms, twenty specimens of 
both sexes (presented by Dr. Nakazawa). 
Across the channel from Singgora, Tale Sap, Siam, 4I metres, 24. i. 1916, two 
males, 10 mm. 
This species is evidently widely distributed in the temperate and tropical parts 
of the Pacific Ocean and is now known from off Java (Hansen), Japan (Nakazawa), 
Chilka Lake, Orissa (Tattersall), Torres Straits and Pacific. Ocean between New 
Caledonia and New Zealand (Colosi) and Siam. 
• Sub-f am. }fYSINAE. 
Nanomysis, gen. nov. 
First, second and fifth pleopods of the male, rudimentary, one- jointed and of 
the same form as the female. Third pleopod of the male with a single -jointed inner 
ramus and a three- jointed outer ramus which is nearly three-times as long as the 
inner ramus, the two terminal joints small, the first joint with three long setae on 
the distal end of the outer margin, the second joint with a single seta on the outer 
distal corner, the third joint with a single terminal seta longer than the joint. 
Fourth pleopod of the male very long, extending to the end of the telson, inner 
ramus single- join ted, outer ramus four- jointed, the first joint half as long as the 
whole ramus and almost twice as long as the inner ramus, second joint slightly longer 
than the third, the terminal joint small and bearing two spiniform setae about four 
times as long as the joint, third joint with a single long and powerful seta on its 
outer distal corner twice as long as the third joint and reaching beyond the terminal 
setae. 
Antennal scale narrowly lanceolate and two- jointed, setose all round. Mastica- 
tory lobes on the second, third and fourth joints of the endopod of the first thoracic 
limb well developed. 
Tarsus of the po.sterior thoracic hmbs four- jointed. 
Inner uropod without spines on the inner margin. 
